diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c index 609c48f38524..8df54b59513a 100644 --- a/tools/testing/selftests/cgroup/test_zswap.c +++ b/tools/testing/selftests/cgroup/test_zswap.c @@ -20,6 +20,7 @@ static int page_size; #define PATH_ZSWAP "/sys/module/zswap" #define PATH_ZSWAP_ENABLED "/sys/module/zswap/parameters/enabled" +#define PATH_ZSWAP_SHRINKER_ENABLED "/sys/module/zswap/parameters/shrinker_enabled" #define PATH_ZSWAP_STORED_PAGES "/sys/kernel/debug/zswap/stored_pages" static int read_int(const char *path, size_t *value) @@ -444,6 +445,16 @@ static int test_zswap_writeback_disabled(const char *root) return test_zswap_writeback(root, false); } +static bool zswap_shrinker_enabled(void) +{ + char value[2]; + + if (read_text(PATH_ZSWAP_SHRINKER_ENABLED, value, sizeof(value)) <= 0) + return 0; + + return value[0] == 'Y'; +} + /* * When trying to store a memcg page in zswap, if the memcg hits its memory * limit in zswap, writeback should affect only the zswapped pages of that @@ -453,6 +464,7 @@ static int test_no_invasive_cgroup_shrink(const char *root) { int ret = KSFT_FAIL; unsigned int off; + long zswpwb_before, zswpwb_after, zswpwb_target; size_t allocation_size = page_size * 1024; unsigned int nr_pages = allocation_size / page_size; char zswap_max_buf[32], mem_max_buf[32]; @@ -488,6 +500,14 @@ static int test_no_invasive_cgroup_shrink(const char *root) if (cg_read_key_long(zw_group, "memory.stat", "zswapped") < 1) goto out; + /* If the shrinker is enabled, try to let the writebacks finish first */ + if (zswap_shrinker_enabled()) + sleep(5); + + zswpwb_before = get_cg_wb_count(zw_group); + if (zswpwb_before < 0) + goto out; + /* Push wb_group memory into zswap with hard-to-compress data to trigger wb */ if (cg_enter_current(wb_group)) goto out; @@ -500,9 +520,13 @@ static int test_no_invasive_cgroup_shrink(const char *root) getrandom(&wb_allocation[off], page_size/4, 0); } - /* Verify that only zswapped memory from gwb_group has been written back */ - if (wait_for_writeback(wb_group, 5000) > 0 && get_cg_wb_count(zw_group) == 0) + /* Verify that only zswapped memory from wb_group has been written back */ + zswpwb_target = wait_for_writeback(wb_group, 5000); + zswpwb_after = get_cg_wb_count(zw_group); + + if (zswpwb_target > 0 && zswpwb_before == zswpwb_after) ret = KSFT_PASS; + out: cg_enter_current(root); if (zw_group) {